This invention relates to cycle exercisers and, in particular, to a cycle exerciser of the dual action type wherein oscillating handlebar levers provide exercise for the muscle groups of the upper body.
U.S. Pat. No. 4,188,030 to Hooper, incorporated herein by reference, discloses a cycle exerciser of the aforementioned type. In this device, the rotary movement of the foot pedals and the oscillating movement of the handlebar levers are timed "so as to achieve a natural balance between upper and lower body movements in a manner similar to walking and running." This is achieved through the use of a rather complex eccentric drive mechanism for the handlebar levers. In one embodiment, an eccentric cam disc rotates with the pedal cranks, and a cam follower having a plurality of rollers embraces the cam disc. In another embodiment, a dual crank arrangement is provided on the main drive shaft, one pair of cranks for the foot pedals and the other pair of cranks for the handlebar levers. In each of these embodiments, the drive for the handlebar levers is about 90.degree. out of phase with the pedal cranks, resulting in the coordinated motion quoted above. Resistance to exercising movement is provided by a vaned wheel driven through sprockets and chains off the main drive shaft.
Several drawbacks are inherent in the design of a product constructed in accordance with the Hooper patent. Due in large part to its complex construction, as described above, manufacturing cost naturally is a concern. In addition, FIG. 5 of the Hooper patent reveals, and experience with a commercial device of the Hooper design confirms, that one inherent feature of the Hooper design may be troublesome to some users. That is, with the foot pedals in the 12 and 6 o'clock positions, one of the handlebar levers resides close to or at its rearmost position, in close proximity to the seat. For users that are accustomed to mounting and dismounting the exerciser by standing on the lower of the two pedals, the proximity of the rearmost handlebar lever to the seat can cause interference during either of these maneuvers. Further, the 12 and 6 o'clock positions of the foot pedals are, respectively, the top and bottom dead center positions of the pedal cranks. In these positions, it is difficult to initiate rotation of the drive shaft by a downward thrust on one of the pedals. A push or a pull on the handlebar levers similarly will not easily initiate rotation of the drive shaft because the eccentrics or cranks for the handlebar levers also are at their dead center positions. Initiation of exercise therefore requires an awkward bend of the foot to push the top pedal forward, or hooking the top pedal from behind with the top of the foot.